A fun little game indeed
Alright, first off let me say that I'm a sucker for the 8 bit style, so I'm perhaps a little biased there, but they were both excellent. I quickly worked out the gameplay and thoroughly enjoyed working towards each new form and exploring with the new abilities of each.
There are some very precise jumps, but I never found any of them impossible, just that they required a few attempts - a good level of challenge.
Reaching the final form and gaining the freedom to explore everywhere at will was a great feeling, as was reaching the end.
However, there are a few small issues. First, although I did not resent the pixel-perfect jumps in themselves, I did start to get frustrated with them when failure meant a long fall and a series of jumps to climb back up again.
Second, while in the first winged form, I found the inability to just jump without using the wings to be incredibly annoying - what I would have expected (and much preferred) would be if the wings only worked if you pressed jump a second time in mid air. This would save the player having to press down to descend to a platform after every single jump while in this form. A third press could then cancel the flight if the player wanted to drop immediately.
Also, although the music was good, I felt it looped a little too quickly.
Despite all that, I very much enjoyed playing, and found it engaging enough to want to collect all the pixels and reach the end, even after having to restart after encountering what I thought was a bug (I ended up with only 63/64 pixels at the small wing form and was completley unable to find the final one).
I'd be very interested to see a sequel!